European Union foreign ministers have agreed to impose sanctions on Ukrainian officials "responsible for violence and excessive force".
In a statement, they said targeted sanctions including asset freezes and visa bans would be introduced "as a matter of urgency".
At least 21 anti-government protesters died in clashes in Kiev on Thursday.
Officials said that one policeman had also died and that 67 police had been captured by protesters.
"No circumstances can justify the repression we are currently witnessing," the statement from EU foreign ministers said.
EU foreign policy chief Catherine Ashton said the "prime responsibility" to get talks between the two sides under way lay with President Viktor Yanukovych.
The BBC's Daniel Sandford witnesses Ukraine's "descent into insanity"
Speaking after an emergency meeting of EU foreign minsters in Brussels, she said ministers had expressed their "dismay" at the latest violence and had agreed to "suspend export licences for equipment for internal repression".
Implementation of the measures "will be taken forward in light of developments in Ukraine", she added.
The EU has until now refrained from imposing sanctions on Ukraine, preferring to emphasise dialogue and compromise.
The US state department had already announced visa bans on 20 members of the Ukrainian government but has not provided any names.
Ukraine's health ministry says 75 people have now died and 571 have been injured in violence since Tuesday.
At least 21 protesters were killed by security forces in Kiev on Thursday following the breakdown of a truce the previous day.
Witnesses have told the BBC that some died as a result of single gunshot wounds, typical of sniper fire.
The authorities said that one policeman had died and that 67 police had been captured by protesters.
Eyewitnesses have told international news agencies that they have counted between 21 and 27 protesters' bodies after clashes in Kiev.
Video footage has emerged apparently showing snipers firing on demonstrators who had been trying to retake their protest camp in Independence Square.
Officials said more than 20 policemen had also been injured.
Witnesses reported live rounds, petrol bombs and water cannon being used at Independence Square during Thursday morning's clashes.
Some armed demonstrators were also reported to be firing towards security forces.
Gunshots pierced the windows of rooms at the Ukraine Hotel, which is serving as the base for all foreign media in Kiev, including the BBC.
Earlier, several dozen protesters were using the lobby as a triage centre for the wounded, and a priest arrived, says the BBC's Kevin Bishop, at the scene.
Protesters - some of them armed - asked hotel guests for blankets to use as bandages.
A statement on the presidential website blamed the opposition for starting the violence, saying the "calls for a truce and dialogue were nothing but a way of playing for time to mobilise and arm militants from Maidan [Independence Square]".
MPs assembled for a session of parliament on Thursday afternoon voted to condemn the recent violence. They also called for the use of weapons against protesters to be banned, and for troops and police deployed against them to be withdrawn.
The session was attended by 239 out of 450 MPs, most of them from opposition parties.
Earlier the foreign ministers of France, Poland and Germany conducted several hours of discussions with Mr Yanukovych on a "roadmap towards a political solution" before going on to talks with opposition leaders.
They returned for another meeting with Mr Yanukovych on Thursday evening.
Polish Prime Minister Donald Tusk said Mr Yanukovych had expressed willingness to hold early elections this year.
The protests first erupted in November when President Yanukovych rejected a landmark association and trade deal with the EU in favour of closer ties with Russia.
Since then, the protests have spread across Ukraine, with the demonstrators' main demand being snap presidential and parliamentary elections.